Lawmakers pressed them on a provision lifting the arms embargo on Iran.
The effort with Turkey could deepen U.S. involvement in Syria.
GOP leaders asked the White House to hand over those terms "immediately."
Lawmakers said Congress should have weighed in on the deal first.
Obama suggested the deal was a historic opportunity that should be seized.
A working group will take the next six months to study lifting the ban.
The Army on Thursday will announce massive troop cuts over the next two years.
Obama was briefed on the fight by officials at the Pentagon.
The changes allow families of captives to offer ransom payments.
The panel gave State until the end of the day to determine if it already had 60 emails.
The House rejected a measure requiring troops to withdraw in 6 months without an AUMF.
Sidney Blumenthal could face as much as 6 hours of questioning.
Kerry had several sharp exchanges, underscoring the White House's hard sell.
The Obama administration called the plan "premature."
Obama said the Iran critics were the same ones who backed the Iraq war.
President Obama called the shooting "heartbreaking.'
Obama trumpted the historic deal Tuesday and warned against efforts to block it.
The looming cuts have already sparked finger-pointing on Capitol Hill.
The low numbers drew criticism from lawmakers already skeptical of the anti-ISIS strategy.
Lawmakers held a ceremonial "pass the gavel" behind closed doors.
The changes will allow American families to communicate with captors and pay ransoms.
Senate Democrats are vowing to block spending bills until they get budget talks.
Blumenthal said the tone was "civil" at the closed-door deposition.
The White House has threatened to veto the measure.